> -----Original Message----- > From: Yuanhan Liu [mailto:yuanhan....@linux.intel.com] > Sent: den 8 december 2016 06:51 > To: Jan Wickbom <jan.wick...@ericsson.com> > Cc: dev@dpdk.org; Patrik Andersson R <patrik.r.anders...@ericsson.com> > Subject: Re: [PATCH] vhost: allow for many vhost user ports > > On Wed, Dec 07, 2016 at 01:23:48PM +0000, Jan Wickbom wrote: > > > On Thu, Dec 01, 2016 at 04:26:50PM +0100, Jan Wickbom wrote: > > > > static int > > > > -fdset_fill(fd_set *rfset, fd_set *wfset, struct fdset *pfdset) > > > > +fdset_fill(struct pollfd *rwfds, struct fdset *pfdset) > ... > > > > + rwfds[i].fd = pfdentry->fd; > > > > + rwfds[i].events = pfdentry->rcb ? POLLIN : 0; > > > > + rwfds[i].events |= pfdentry->wcb ? POLLOUT : > > > 0; > > > > > > Another thing is we don't have to re-init this rwfds array again > > > and again. Instead, we could > > > > > > - set it up correctly when fdset_add is invoked: set the fd and > > > events. > > > > > > - reset revents when it's been handled at fdset_event_dispatch(). > > > > > > - swap with the last one and shrink the array on fd delete > > > > > > Could you make a follow up patch for that? > > > > I don't see how that could easily be done. The loop index, i, is a direct > reference between > > an entry in the rwfds array and an entry in the pfdset array. It should stay > like that while we are > > hanging in the poll(). If an entry in the pfdset array is removed while we > are hanging in the poll() > > and we then immediately replaces it with the last entry in the array we will > end up in trouble if the > > revent gets set for the "replaced" index. The direct reference is gone. > > Or am I missing something? > > Yes, we should not shrink the rwfds during the poll, but we could later, at > the end of the while() loop.
Did something in v3, please have a look. > > Talking about that, you should not invoke fdset_shrink() inside fdset_del(), > since it could be in the poll stage. Thanks! Forgot this! Will send a v4 > > --yliu
